Ukraine's Attorney General Yuriy Lutsenko on Tuesday offered his resignation after an anti-corruption campaigner died after a brutal attack which law enforcement officers appear unable to solve.

Kateryna Handziuk, who worked as an adviser to the mayor of Ukraine's southern city Kherson, died on Sunday in hospital after she was seriously injured in an acid attack in July.

Her death sparked fresh condemnation of the government by civil society activists, who accuse the authorities of being unable to complete the investigation and demanded the resignation of the attorney general and interior minister.

"I am offering my resignation today," Lutsenko told Ukrainian lawmakers during his investigation report.

Parliament must approve the decision before it takes effect.

Lutsenko accused activists of putting pressure on the investigation and leaking information, making it difficult to establish who was behind Handziuk's murder.

Handziuk, 33, was leaving home early on the morning of July 31 when a man poured about a liter of acid over her and ran away.

She was immediately hospitalized in a serious condition, with burns on 30 percent of her body, including her upper torso, arms, and face.

Handziuk was an outspoken critic of corruption in the law enforcement agencies, particularly in the police.

The country has seen a recent increase in attacks on anti-corruption activists and campaigners.

Both the European Union and the U.S. called the attacks unacceptable and urged authorities to bring the perpetrators to justice.

In 2017, the body of human rights activist Iryna Nozdrovska was found in a river outside Kiev.

In July, Vitaliy Oleshko, a former volunteer fighter in the rebel Ukrainian east and a local activist, was shot dead outside a hotel in the southeastern city of Berdyansk.